Diabetic retinopathy is best diagnosed with a comprehensive dilated eye exam. For this exam, drops placed in your eyes widen (dilate) your pupils to allow your doctor to better view inside your eyes. The drops may cause your close vision to blur until they wear off, several hours later.
During the exam, your eye doctor will look for:
- Abnormal blood vessels
- Swelling, blood or fatty deposits in the retina
- Growth of new blood vessels and scar tissue
- Bleeding in the clear, jelly-like substance that fills the center of the eye (vitreous)
- Retinal detachment
- Abnormalities in your optic nerve
In addition, your eye doctor may:
- Test your vision
- Measure your eye pressure to test for glaucoma
- Look for evidence of cataracts
With your eyes dilated, your doctor takes pictures of the inside of your eyes. Then your doctor will inject a special dye into your arm vein and take more pictures as the dye circulates through your eyes' blood vessels. Your doctor can use the images to pinpoint blood vessels that are closed, broken down or leaking fluid.
Optical coherence tomography
Your eye doctor may request an optical coherence tomography (OCT) exam. This imaging test provides cross-sectional images of the retina that show the thickness of the retina, which will help determine whether fluid has leaked into retinal tissue. Later, OCT exams can be used to monitor how treatment is working.
Treatment, which depends largely on the type of diabetic retinopathy you have and how severe it is, is geared to slowing or stopping progression of the condition.
Early diabetic retinopathy
If you have mild or moderate nonproliferative diabetic retinopathy, you may not need treatment right away. However, your eye doctor will closely monitor your eyes to determine when you might need treatment.
Work with your diabetes doctor (endocrinologist) to determine if there are ways to improve your diabetes management. When diabetic retinopathy is mild or moderate, good blood sugar control can usually slow the progression.
Advanced diabetic retinopathy
If you have proliferative diabetic retinopathy or macular edema, you'll need prompt surgical treatment. Depending on the specific problems with your retina, options may include:
Photocoagulation. This laser treatment, also known as focal laser treatment, can stop or slow the leakage of blood and fluid in the eye. During the procedure, leaks from abnormal blood vessels are treated with laser burns.
Focal laser treatment is usually done in your doctor's office or eye clinic in a single session. If you had blurred vision from macular edema before surgery, the treatment might not return your vision to normal, but it's likely to reduce the chance the macular edema may worsen.
Panretinal photocoagulation. This laser treatment, also known as scatter laser treatment, can shrink the abnormal blood vessels. During the procedure, the areas of the retina away from the macula are treated with scattered laser burns. The burns cause the abnormal new blood vessels to shrink and scar.
It's usually done in your doctor's office or eye clinic in two or more sessions. Your vision will be blurry for about a day after the procedure. Some loss of peripheral vision or night vision after the procedure is possible.
- Vitrectomy. This procedure uses a tiny incision in your eye to remove blood from the middle of the eye (vitreous) as well as scar tissue that's tugging on the retina. It's done in a surgery center or hospital using local or general anesthesia.
Injecting medicine into the eye. Your doctor may suggest injecting medication into the vitreous in the eye. These medications, called vascular endothelial growth factor (VEGF) inhibitors, may help stop growth of new blood vessels by blocking the effects of growth signals the body sends to generate new blood vessels.
Your doctor may recommend these medications, also called anti-VEGF therapy, as a stand-alone treatment or in combination with panretinal photocoagulation. While studies of anti-VEGF therapy in the treatment of diabetic retinopathy are promising, this approach is not yet considered standard.
Surgery often slows or stops the progression of diabetic retinopathy, but it's not a cure. Because diabetes is a lifelong condition, future retinal damage and vision loss are still possible.
Even after treatment for diabetic retinopathy, you'll need regular eye exams. At some point, additional treatment may be recommended.
Several alternative therapies have suggested some benefits for people with diabetic retinopathy, but more research is needed to understand whether these treatments are effective and safe.
Be sure to let your doctor know if you are taking any herbs or supplements. They have the potential to interact with other medications, or cause complications in surgery, such as excessive bleeding.
It's vital not to delay standard treatments to try unproven therapies. Early treatment is the best way to prevent vision loss.
Coping and support
The thought that you might lose your sight can be frightening, and you may benefit from talking to a therapist or finding a support group. Ask your doctor for referrals.
If you've already lost vision, ask your doctor about low-vision products, such as magnifiers, and services that can make daily living easier.
Preparing for your appointment
The American Diabetes Association (ADA) recommends that anyone who's older than 10 with type 1 diabetes have his or her first eye exam within five years of being diagnosed with diabetes.
If you have type 2 diabetes, the ADA advises getting your initial eye exam at the time of your diagnosis, because you may have had diabetes for some time without knowing it.
If there's no evidence of retinopathy on your initial exam, the ADA recommends that people with diabetes get dilated and comprehensive eye exams at least every two years. If you have any level of retinopathy, you'll need eye exams at least annually. Ask your eye doctor what he or she recommends.
The ADA recommends that women with diabetes have an eye exam before becoming pregnant or during the first trimester of pregnancy and be closely followed during the pregnancy and up to one year after giving birth. Pregnancy can sometimes cause diabetic retinopathy to develop or worsen.
Here's some information to help you get ready for your eye appointment.
What you can do
- Write a brief summary of your diabetes history, including when you were diagnosed; medications you have taken for diabetes, now and in the past; recent average blood sugar levels; and your last few hemoglobin A1C readings, if you know them.
- List other medications, vitamins and supplements you take, and the dosage.
- List your symptoms, if any. Include any that may seem unrelated to potential eye problems.
- Ask a family member or friend to go with you, if possible. Someone who accompanies you can help remember the information you receive. Also, because your eyes have been dilated, a companion can drive you home.
- List questions for your doctor.
For diabetic retinopathy, some basic questions to ask your doctor include:
- How is diabetes affecting my vision?
- Do I need other tests?
- Is this condition temporary or long lasting?
- What treatments are available, and which do you recommend?
- What side effects might I expect from treatment?
- I have other health conditions. How can I best manage them together?
- If I control my blood sugar, will my eye symptoms go away?
- What do my blood sugar goals need to be to protect my eyes?
- Can you recommend services for people with visual impairment?
Don't hesitate to ask other questions you have.
What to expect from your doctor
Your doctor is likely to ask you a number of questions, including:
- Do you have eye symptoms, such as blurred vision or floaters?
- How long have you had symptoms?
- In general, how well are you controlling your diabetes?
- What was your last hemoglobin A1C?
- Do you have other health conditions, such as high blood pressure or high cholesterol?
- Have you had eye surgery?